Tularemie je zoonóza, jejíž původcem je Francisella tularensis, gramnegativní aerobní bakterie patřící do třídy Gammaproteobacteria a čeledi Francisellaceae. Navzdory skutečnosti, že F. tularensis může mít významný dopad na zdraví člověka, existuje o aktuálním výskytu tohoto patogenu v různých hematofágních členovcích pouze velmi málo údajů. Cílem studie bylo provést rozsáhlý molekulární screening různých potenciálních hematofágních vektorů: klíšťat (4348 jedinců druhů Ixodes ricinus, Dermacentor reticulatus a Haemaphysalis concinna), komárů (4100 jedinců druhu Aedes vexans) a muchniček (6900 jedinců Simulium spp.) na přítomnost F. tularensis na Břeclavsku v roce 2022. Pozitivní byly pouze 2 vzorky, které obsahovaly DNA specifickou pro F. tularensis subsp. holarctica. Oba vzorky pocházely z klíštěte D. reticulatus a to jak po infestaci srnce, tak jednoho směsného vzorku nasbíraných klíšťat (n = 10). Oba pozitivní vzorky byly sekvenovány a byla potvrzena přítomnost F. tularensis subsp. holarctica. Přítomnost

Tularemia is a zoonosis caused by Francisella tularensis, a gram-negative aerobic bacterium belonging to the class of Gammaproteobacteria and the family Francisellaceae. Despite its undeniable importance for human health, there is little data on the current distribution of F. tularensis in various hematophagous arthropods. The aim of this study was to perform a mass molecular screening of different possible hematophagous vectors: ticks (4348 ticks of the species Ixodes ricinus, Dermacentor reticulatus, and Haemaphysalis concinna), mosquitoes (4100 specimens of Aedes vexans), and blackflies (6900 specimens of the Simulium spp.) for the presence of F. tularensis in the Břeclav district in 2022. Only two specimens were positive for the specific DNA of Francisella tularensis subsp. holarctica. Both samples originated from D. reticulatus, one collected from infested roe deer and the other included in a pooled sample (n = 10). Both positive samples were sequenced, and the presence of F. tularensis subsp. holarctica was confirmed. In addition, the absence of F. tularensis in mosquitoes and black flies was documented.

• MeSH
• Francisella tularensis * patogenita   MeSH
• genetické techniky MeSH
• infekce přenášené vektorem * MeSH
• komáří přenašeči mikrobiologie   MeSH
• kontrola infekčních nemocí * metody   MeSH
• lidé MeSH
• nemoci přenášené klíšťaty epidemiologie   mikrobiologie   přenos   MeSH
• Simuliidae mikrobiologie   MeSH
• tularemie epidemiologie   mikrobiologie   přenos   MeSH
• zdroje nemoci mikrobiologie   MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND: Salivary glands from blood-feeding arthropods secrete several molecules that inhibit mammalian hemostasis and facilitate blood feeding and pathogen transmission. The salivary functions from Simulium guianense, the main vector of Onchocerciasis in South America, remain largely understudied. Here, we have characterized a salivary protease inhibitor (Guianensin) from the blackfly Simulium guianense. MATERIALS AND METHODS: A combination of bioinformatic and biophysical analyses, recombinant protein production, in vitro and in vivo experiments were utilized to characterize the molecula mechanism of action of Guianensin. Kinetics of Guianensin interaction with proteases involved in vertebrate inflammation and coagulation were carried out by surface plasmon resonance and isothermal titration calorimetry. Plasma recalcification and coagulometry and tail bleeding assays were performed to understand the role of Guianensin in coagulation. RESULTS: Guianensin was identified in the sialotranscriptome of adult S. guianense flies and belongs to the Kunitz domain of protease inhibitors. It targets various serine proteases involved in hemostasis and inflammation. Binding to these enzymes is highly specific to the catalytic site and is not detectable for their zymogens, the catalytic site-blocked human coagulation factor Xa (FXa), or thrombin. Accordingly, Guianensin significantly increased both PT (Prothrombin time) and aPTT (Activated partial thromboplastin time) in human plasma and consequently increased blood clotting time ex vivo. Guianensin also inhibited prothrombinase activity on endothelial cells. We show that Guianensin acts as a potent anti-inflammatory molecule on FXa-induced paw edema formation in mice. CONCLUSION: The information generated by this work highlights the biological functionality of Guianensin as an antithrombotic and anti-inflammatory protein that may play significant roles in blood feeding and pathogen transmission.

• MeSH
• antiflogistika farmakologie   MeSH
• endoteliální buňky MeSH
• hemostatika * MeSH
• hemostáza MeSH
• lidé MeSH
• myši MeSH
• savci MeSH
• Simuliidae * MeSH
• slinné proteiny a peptidy farmakologie   MeSH
• zánět MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Intramural MeSH

• MeSH
• Culicidae MeSH
• lidé MeSH
• paraziti * MeSH
• Simuliidae MeSH
• Trombiculidae MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

BACKGROUND: In onchocerciasis endemic areas in Africa, heterogenous biting rates by blackfly vectors on humans are assumed to partially explain age- and sex-dependent infection patterns with Onchocerca volvulus. To underpin these assumptions and further improve predictions made by onchocerciasis transmission models, demographic patterns in antibody responses to salivary antigens of Simulium damnosum s.l. are evaluated as a measure of blackfly exposure. METHODOLOGY/PRINCIPAL FINDINGS: Recently developed IgG and IgM anti-saliva immunoassays for S. damnosum s.l. were applied to blood samples collected from residents in four onchocerciasis endemic villages in Ghana. Demographic patterns in antibody levels according to village, sex and age were explored by fitting generalized linear models. Antibody levels varied between villages but showed consistent patterns with age and sex. Both IgG and IgM responses declined with increasing age. IgG responses were generally lower in males than in females and exhibited a steeper decline in adult males than in adult females. No sex-specific difference was observed in IgM responses. CONCLUSIONS/SIGNIFICANCE: The decline in age-specific antibody patterns suggested development of immunotolerance or desensitization to blackfly saliva antigen in response to persistent exposure. The variation between sexes, and between adults and youngsters may reflect differences in behaviour influencing cumulative exposure. These measures of antibody acquisition and decay could be incorporated into onchocerciasis transmission models towards informing onchocerciasis control, elimination, and surveillance.

• MeSH
• dítě MeSH
• dospělí MeSH
• hmyz - vektory imunologie   parazitologie   MeSH
• imunoglobulin G krev   MeSH
• imunoglobulin M krev   MeSH
• kousnutí a bodnutí hmyzem epidemiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• Onchocerca volvulus růst a vývoj   MeSH
• onchocerkóza epidemiologie   přenos   MeSH
• předškolní dítě MeSH
• protilátky krev   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Simuliidae imunologie   parazitologie   MeSH
• sliny imunologie   MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Simulium damnosum sensu lato (s.l.) blackflies transmit Onchocerca volvulus, a filarial nematode that causes human onchocerciasis. Human landing catches (HLCs) is currently the sole method used to estimate blackfly biting rates but is labour-intensive and questionable on ethical grounds. A potential alternative is to measure host antibodies to vector saliva deposited during bloodfeeding. In this study, immunoassays to quantify human antibody responses to S. damnosum s.l. saliva were developed, and the salivary proteome of S. damnosum s.l. was investigated. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples from people living in onchocerciasis-endemic areas in Ghana were collected during the wet season; samples from people living in Accra, a blackfly-free area, were considered negative controls and compared to samples from blackfly-free locations in Sudan. Blackflies were collected by HLCs and dissected to extract their salivary glands. An ELISA measuring anti-S. damnosum s.l. salivary IgG and IgM was optimized and used to quantify the humoral immune response of 958 individuals. Both immunoassays differentiated negative controls from endemic participants. Salivary proteins were separated by gel-electrophoresis, and antigenic proteins visualized by immunoblot. Liquid chromatography mass spectrometry (LC-MS/MS) was performed to characterize the proteome of S. damnosum s.l. salivary glands. Several antigenic proteins were recognized, with the major ones located around 15 and 40 kDa. LC-MS/MS identified the presence of antigen 5-related protein, apyrase/nucleotidase, and hyaluronidase. CONCLUSIONS/SIGNIFICANCE: This study validated for the first time human immunoassays that quantify humoral immune responses as potential markers of exposure to blackfly bites. These assays have the potential to facilitate understanding patterns of exposure as well as evaluating the impact of vector control on biting rates. Future studies need to investigate seasonal fluctuations of these antibody responses, potential cross-reactions with other bloodsucking arthropods, and thoroughly identify the most immunogenic proteins.

• MeSH
• dítě MeSH
• dospělí MeSH
• ELISA MeSH
• hmyz - vektory fyziologie   MeSH
• imunoglobulin G krev   MeSH
• imunoglobulin M krev   MeSH
• kousnutí a bodnutí hmyzem epidemiologie   imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• onchocerkóza MeSH
• předškolní dítě MeSH
• senioři MeSH
• Simuliidae fyziologie   MeSH
• sliny * MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Ghana MeSH
• Súdán MeSH

• MeSH
• cestovní nemoci MeSH
• ivermektin terapeutické užití   MeSH
• lidé MeSH
• onchocerkóza oční * parazitologie   prevence a kontrola   terapie   MeSH
• onchocerkóza * parazitologie   patologie   prevence a kontrola   terapie   MeSH
• opomíjené nemoci MeSH
• Simuliidae parazitologie   patogenita   MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Afrika MeSH

Sedentary bird species are suitable model hosts for identifying potential vectors of avian blood parasites. We studied haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) in the Ore Mountains of the Czech Republic using molecular detection methods. Sex of owl nestlings was scored using molecular sexing based on fragment analysis of PCR-amplified CHD1 introns. Observed infection prevalences in nestlings and adult owls were 51 and 86 %, respectively. Five parasite lineages were detected. Most of the infections comprised the Leucocytozoon AEFUN02 and STOCC06 lineages that probably refer to distinct Leucocytozoon species. Other lineages were detected only sporadically. Mixed infections were found in 49 % of samples. The main factor affecting the probability of infection was host age. No effect of individual sex on infection probability was evidenced. The youngest infected nestling was 12 days old. High parasite prevalence in the Tengmalm's Owl nestlings suggests that insect vectors must enter nest boxes to transmit parasites before fledging. Hence, we placed sticky insect traps into modified nest boxes, collected potential insect vectors, and examined them for the presence of haemosporidian parasites using molecular detection. We trapped 201 insects which were determined as biting midges from the Culicoides genus and two black fly species, Simulium (Nevermannia) vernum and Simulium (Eusimulium) angustipes. Six haemosporidian lineages were detected in the potential insect vectors, among which the Leucocytozoon lineage BT2 was common to the Tengmalm's Owl and the trapped insects. However, we have not detected the most frequently encountered Tengmalm's Owl Leucocytozoon lineages AEFUN02 and STOCC06 in insects.

• MeSH
• Ceratopogonidae parazitologie   MeSH
• Haemosporida genetika   izolace a purifikace   MeSH
• hmyz - vektory parazitologie   MeSH
• nemoci ptáků epidemiologie   parazitologie   přenos   MeSH
• polymerázová řetězová reakce MeSH
• prevalence MeSH
• protozoální infekce zvířat epidemiologie   parazitologie   přenos   MeSH
• sexuální faktory MeSH
• Simuliidae parazitologie   MeSH
• Stringiformes parazitologie   MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

The prevalences of heteroxenous parasites are influenced by the interplay of three main actors: hosts, vectors, and the parasites themselves. We studied blood protists in the nesting populations of raptors in two different areas of the Czech Republic. Altogether, 788 nestlings and 258 adult Eurasian sparrowhawks (Accipiter nisus) and 321 nestlings and 86 adult common buzzards (Buteo buteo) were screened for parasites by the microscopic examination of blood smears and by cultivation. We examined the role of shared vectors and parasite phylogenetic relationships on the occurrence of parasites. In different years and hosts, trypanosome prevalence ranged between 1.9 and 87.2 %, that of Leucocytozoon between 1.9 and 100 %, and Haemoproteus between 0 and 72.7 %. Coinfections with Leucocytozoon and Trypanosoma, phylogenetically distant parasites but both transmitted by blackflies (Simuliidae), were more frequent than coinfections with Leucocytozoon and Haemoproteus, phylogenetically closely related parasites transmitted by different vectors (blackflies and biting midges (Ceratopogonidae), respectively). For example, 16.6 % buzzard nestlings were coinfected with Trypanosoma and Leucocytozoon, while only 4.8 % with Leucocytozoon and Haemoproteus and 0.3 % with Trypanosoma and Haemoproteus. Nestlings in the same nest tended to have the same infection status. Furthermore, prevalence increased with the age of nestlings and with Julian date, while brood size had only a weak negative/positive effect on prevalence at the individual/brood level. Prevalences in a particular avian host species also varied between study sites and years. All these factors should thus be considered while comparing prevalences from different studies, the impact of vectors being the most important. We conclude that phylogenetically unrelated parasites that share the same vectors tend to have similar distributions within the host populations of two different raptor species.

• MeSH
• dravci parazitologie   MeSH
• Falconiformes parazitologie   MeSH
• fylogeneze MeSH
• Haemosporida klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• hmyz - vektory parazitologie   fyziologie   MeSH
• hostitelská specificita MeSH
• nemoci ptáků epidemiologie   parazitologie   přenos   MeSH
• prevalence MeSH
• protozoální infekce zvířat epidemiologie   parazitologie   přenos   MeSH
• ptáci parazitologie   MeSH
• Simuliidae parazitologie   fyziologie   MeSH
• Trypanosoma klasifikace   genetika   izolace a purifikace   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Trypanosomes are known as widespread blood parasites of birds; however, knowledge of their prevalences in vectors and their overall biodiversity is rather limited. To assess the prevalences in potential vectors, we have microscopically examined ornithophilic bloodsucking Diptera (Culicidae, Simuliidae and Hippoboscidae) for the presence of trypanosomatids in their guts. In total, 3270 specimens were dissected, namely Culex pipiens Linnaeus, 1758 (n = 898), C. modestus Ficalbi, 1890 (136), Simulium vernum (Macquart, 1838) (1455), S. angustipes Edwards, 1915 (221) and Ornithomyia avicularia (Linnaeus, 1758) (560). All insect species were found to be infected with trypanosomatids, and the prevalence ranged from 4 to 8% but reached 60% in S. vernum. Blackflies and hippoboscids exclusively harboured trypanosomes (both T. cf. avium s.s. Danilewsky, 1885; T. corvi/culicavium group in hippoboscids). Mosquitoes were infected with T. culicavium Votypka, 2012 and T. avium s. l. but also with monoxenous parasites, namely Crithidia brevicula Frolov and Malysheva, 1989, and Paratrypanosoma confusum Votypka and Lukes, 2013. Only 4% of the isolated parasite strains were monoxenous whereas the majority were avian trypanosomes, confirming the vectorial status of the studied insects.

• MeSH
• Culicidae parazitologie   MeSH
• Diptera parazitologie   MeSH
• dravci parazitologie   MeSH
• hmyz - vektory parazitologie   MeSH
• Simuliidae parazitologie   MeSH
• Trypanosomatina izolace a purifikace   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

• Klíčová slova
• 2-heptanone, Tabanidae, ovádi,
• MeSH
• Aedes patogenita   růst a vývoj   účinky léků   MeSH
• anestetika MeSH
• Anopheles anatomie a histologie   patogenita   růst a vývoj   MeSH
• Anoplura MeSH
• černá vdova MeSH
• deratizace * MeSH
• dezinsekce * metody   MeSH
• horečka Lassa diagnóza   etiologie   mortalita   přenos   MeSH
• ketony farmakologie   škodlivé účinky   terapeutické užití   MeSH
• klíšťata patogenita   MeSH
• kongresy jako téma MeSH
• kontaminace potravin MeSH
• kousnutí a bodnutí hmyzem * MeSH
• kur domácí parazitologie   MeSH
• lidé MeSH
• malárie epidemiologie   mortalita   prevence a kontrola   přenos   MeSH
• pavouci MeSH
• Sarcoptes scabiei parazitologie   patogenita   růst a vývoj   MeSH
• Simuliidae MeSH
• Trombiculidae patogenita   růst a vývoj   MeSH
• včely MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH